The crucial properties of such a light axion are generic and do not depend on the details of the putative UV completion. An important byproduct of this construction is an enhancement of all axion interactions which is universal, that is, model-independent and equal for all axion couplings, at fixed \(m_a\) , see Fig. (REF ). The detailed exploration of the \(Z_{\mathcal {N}}\)  paradigm and of the phenomenological constraints which do not require the axion to account for DM can be found in Ref. [1]}.
It is particularly enticing that experiments set a priori to hunt only for ALPs may in fact be targeting solutions to the strong CP problem. For instance,
ALPS II is shown to be able to probe the \(Z_{\mathcal {N}}\)  scenario here discussed down to
\({\mathcal {N}}\sim 25\)  for a large enough axion-photon coupling, while IAXO and BabyIAXO may test the whole \({\mathcal {N}}\)  landscape for values of that coupling even smaller, see Fig. (REF ).
